Do you know what type of cast they will use on Diva? easy child had a cast due to a crushed hand last summer. It was fibreglass, and he was able to go swimming with it. It dried very quickly, and we didn't have to use the hair dryer or anything.
Now, with the surgical incision it might be a different story. If that's the case, then all the advice above about resin patio chairs, plastic contractor bags with elastics, etc. holds.
It might be worth a chat with the doctor about the type of cast, whether it can get wet, how to handle the incision and skin breakdown, and all that.
